Objective 12


In order to find if two points lie on your parabola you must first have an equation. You can find if your two points lie on the parabola two ways:
  1. graphing calculator
  2. graphmatica

Graphing Calculator


Ex) Y=a(x+4)^2+q running through points (-4,1) (-5,4)
Take your posible numbers for a and q and substitute them in one at a time under your Y= menu
key press
1. Y=
2. input equation with substatuted numbers
3. graph
4. 2nd trace
5. value
6. put in your x value that you need ( -4 or -5 in this example)
7. check if your line goes throught the point you chose
8. repeat 4-7 with second x value

You need to repeat those steps for all the posible a and q numbers untill you find one that works.
The possible a and q values are:
a=1, q=3
a=4, q=1
a=4, q=2
a=3, q=1
The corect answer is Y=3(x+4)^2+1
gggg.JPG

Graphmatica


Ex) Y=a(X+8)^2+q running through points (-8,-3) (-6,5)
First you must input your possible numbers for a and q in the top bar

Run through all your posible a and q values checking the intersept points for each set of variables.
1. input your equation with the first set of variables
2. find the points and zoom in to be sure if it intersects
3. check all sets of variables with bothe intersections untill you fint answer

Possible a and q variables:
a=2, q=-2
a=-2, q=-2
a=2, q=-2
a=1, q=-3
The corect answer is Y=2(X+8)^2-3
fff.JPG

Summery


If you wanted to find the answer quickly graphmatica is faster but you might want to check your calculator to be certian you are correct.